A. Field of the Invention
The present invention relates to multiple disk clutches for an automatic transmission of an automobile or the like. More specifically, the present invention relates to a multiple disk clutch having structure for supplying lubricating oil to friction pads or plates of a clutch.
B. Description of the Background Art
Generally, a multiple disk clutch used in an automatic transmission of an automobile or the like has a plurality of input friction plates and a plurality of output friction plates which are alternately arranged relative to each other. The multiple disk clutch also has a cylindrical input member arranged radially inside these friction plates and a cylindrical output member arranged radially outside the friction plates. Each input friction plate has at least one claw located at its inner periphery. The claws of the input friction plates movably engage grooves formed at the outer periphery of the cylindrical input member for movement in an axial direction. Each output friction plate has its at least one claw located at its outer periphery. The claws of the output friction plates movably engage grooves formed at the inner periphery of the cylindrical output member for relative axial movement.
In the multiple disk clutch, lubricating oil is typically supplied to the surfaces of the friction plates for preventing overheating and abnormal abrasion of the friction plates. The lubricating oil is generally supplied from an inner cylindrical member located near the axis of rotation. More specifically, the lubricating oil is supplied through an appropriate oil passage to an inner space inside of the inner cylindrical member, i.e., a cylindrical member located at a radially inner position, and then is supplied from the inner space by a centrifugal force to the surfaces of the friction plates through oil apertures formed in the inner cylindrical member.
In the prior art, the lubricating oil is typically supplied to many parts of the clutch. Thus, the prior art clutches do not efficiently supply the lubricating oil into the oil apertures of the inner cylindrical member from the radially inner space to the friction plates. Rather, in the prior art clutches, a large amount of oil unavoidably flows to other surface areas of the clutch than the surfaces of the friction plates.